Just received my 1st shipment from Layne Labratories (http://www.laynelabs.com), and I'm very pleased!
Ordered 25 pinky rats and 25 fuzzy rats. I chose to go with them over other vendors because I could order so few quantities of small rats (I don't need 100 pinkies!).
The package was shipped FedEx 2 day from their location in California to my home in Central IL. I was provided with a tracking # and they also called yesterday to let me know it was on its way.
The rats were packed in plastic bags, in an insulated bag with the dry ice (separate plastic bag), inside styrofoam, inside the cardboard shipping box. The rats were still completely rock solid frozen when they arrived here and there was still quite a bit of dry ice left. The rats were clean and there was absolutely no sign of blood, bedding, etc. None were frozen together.
I will definitely be returning to Layne Labs for my future rat-purchasing needs!